Radiopacity modulated radiopaque marker and stent graft using same

Abstract

In one aspect, a radiopaque marker for a medical implant, such as a stent graft for aortic aneurism repair, includes a first radiopaque component connected to a second radiopaque component by a connection. The first radiopaque component includes a non-biodegradable radiopaque body. The radiopaque marker has a first configuration and a second configuration that differ from one another in at least one of volume and shape such that the first and second configurations produce different radiographic images. This change in radiopacity can provide useful information to a surgeon in the event that reintervention becomes necessary.

What is claimed is: 
     
         1 . A radiopacity modulated radiopaque marker for a medical implant comprising:
 a first radiopaque component;   a second radiopaque component connected to the first radiopaque component by a connection;   wherein the first radiopaque component includes a non-biodegradable radiopaque body;   wherein the radiopaque marker has first configuration and a second configuration that differs from the first configuration in at least one of volume and shape such that the first and second configurations produce different radiographic images.   
     
     
         2 . The radiopaque marker of  claim 1  wherein the non-biodegradable radiopaque body is an integral block of metallic material. 
     
     
         3 . The radiopaque marker of  claim 2  wherein the second radiopaque component includes a biodegradable coating covering at least a portion of the integral block of metallic material. 
     
     
         4 . The radiopaque marker of  claim 1  wherein at least one of the first radiopaque component, the second radiopaque component and the connection define a hole therethrough sized to receive at least one of a suture and a stent strut to facilitate attachment to a medical implant. 
     
     
         5 . The radiopaque marker of  claim 1  wherein the integral block of metallic material is a first integral block of metallic material;
 the second radiopaque component includes a second integral block of metallic material; and 
 the connection changes shape responsive to a stimulus. 
 
     
     
         6 . The radiopaque marker of  claim 5  wherein the stimulus includes contact with blood. 
     
     
         7 . The radiopaque marker of  claim 6  wherein the connection is biased from a first shape corresponding to the first configuration toward a second shape corresponding to the second configuration;
 a biodegradable restraint holding the connection in the first shape; and 
 wherein the connection changes from the first shape to the second shape responsive to degradation of biodegradable restraint. 
 
     
     
         8 . The radiopaque marker of  claim 5  wherein the stimulus includes exposure to a magnetic field. 
     
     
         9 . The radiopaque marker of  claim 5  wherein the stimulus includes exposure to light. 
     
     
         10 . The radiopaque marker of  claim 5  wherein a spatial relationship of the first integral block of radiopaque metallic material to the second integral block of radiopaque metallic material is different in the first configuration relative to the second configuration. 
     
     
         11 . The radiopaque marker of  claim 1  wherein first configuration produces a brighter radiopaque image than the second configuration. 
     
     
         12 . The radiopaque marker of  claim 1  wherein first configuration produces a smaller radiopaque image than the second configuration. 
     
     
         13 . A stent graft comprising:
 a stent;   a fabric tube attached to the stent;   at least one radiopacity modulated radiopaque marker attached to at least one of the stent and the fabric tube;   wherein the radiopaque marker includes a first radiopaque component and a second radiopaque component connected to the first radiopaque component by a connection;   wherein the first radiopaque component includes a non-biodegradable radiopaque body;   wherein the radiopaque marker has first configuration and a second configuration that differs from the first configuration in at least one of volume and shape such that the first and second configurations produce different radiographic images.   
     
     
         14 . The stent graft of  claim 13  wherein first configuration produces a brighter radiopaque image than the second configuration. 
     
     
         15 . The stent graft of  claim 13  wherein first configuration produces a smaller radiopaque image than the second configuration. 
     
     
         16 . The stent graft of  claim 13  wherein the non-biodegradable radiopaque body is an integral block of metallic material; and
 wherein the second radiopaque component includes a biodegradable coating in contact with the integral block of metallic material. 
 
     
     
         17 . The stent graft of  claim 13  wherein at least one of the first radiopaque component, the second radiopaque component and the connection define a hole therethrough; and
 the hole receives at least one of a suture tied to the fabric tube and a stent strut of the stent. 
 
     
     
         18 . The stent graft of  claim 13  wherein the integral block of metallic material is a first integral block of metallic material;
 the second radiopaque component includes a second integral block of metallic material; and 
 the connection changes shape responsive to a stimulus. 
 
     
     
         19 . The stent graft of  claim 18  wherein the stimulus includes contact with blood. 
     
     
         20 . The stent graft of  claim 5  wherein the stimulus includes exposure to at least one of a magnetic field and light.